Development of High Yielded Sn-Doped Porous Carbons for Selective CO₂ Capture

The use of porous carbons for selective CO₂ separation attracts increasing attention. Owing to low thermostability of porous polymers, low yield is the major concern of porous carbons. To obtain porous carbons with high yield, the development of thermostable porous polymers is highly expected. Herein, high yielded (70% for 700 °C and 64% for 800 °C) Sn-doped porous carbons (SnPCs) have been constructed through KOH-assisted carbonization of Sn-containing polymer. Notably, SnPC-700 (218.5 mg·g^-1) demonstrates higher CO₂ adsorption capacity than the reference sample prepared without KOH, SnPC-700r (188.3 mg·g^-1), indicating the importance of KOH-assisted activation. Carbonization temperature has an effect on the adsorption capacity of resultant materials, and high carbonization temperature leads to better adsorption capacity on CO₂. SnPC-800 is able to capture 242.8 mg·g^-1 of CO₂, which is better than some benchmarks including BILP-7 (193.0 mg·g^-1), PAF-1-450 (196.4 mg·g^-1), and FCTF-1 (205.5 mg·g^-1). More importantly, SnPC-800 demonstrates good selectivity of CO₂ over CH₄ (31.1). Thus, high yield and good performance upon CO₂ adsorption capacity and selectivity over CH₄ make SnPCs attractive candidates for the removal of CO₂ from natural gas.